old thread but worth reviving- the fix for a Jennings that doesn't feed/extract/eject, is a new slide, at the cost of only $25. No matter if you have the early slide, later slide, the soft material will eventually wear. The slide then moves further forward, due to pounded in bolt face. That closes up headspace, and moves the extractor claw out to the right, off the case rim. Then is fails to extract. The empty shell may still blow back due to the force of firing, but will stovepipe or cause a jam, from not contacting the ejector blade. Just addressing the extractor issue, ignores another serious issue- the closing up of headspace eventually causes slam fires when just chambering a round from a fresh full clip, or causes chain fires, i.e. 2 or 3 shots start going off in succession, from only one trigger pull. That's because the breach bolt face starts to "slam fire" the rounds without needing the firing pin, the bolt face is able to ignite the rimfire primer like a hammer and anvil, from lack of headspace.
The problem is not only pre-70,xxx serial numbers. Mine has a 500,xxx serial number.
VERY DANGEROUS at times, I had (2) slam fires while chambering first rounds from fresh clips, and 3 chain fires so far. Fortunately the barrel was pointed in a safe direction by instinct and habit, and the bullets just went into the target backstop, or ground.
You can fix an old worn out slide albeit somewhat temporarily. File the extractor slot in the barrel area deeper, so there is clearance to fully close the slide, and the extractor to stay engaged on case head. (the extractor should not move outward to the right when the slide is closed)
If the gun has developed closed up headspace, disassemble it and remove the slide, and using a small flat file, file the barrel chamber face flat, to add headspace. The barrel typically sticks out backwards just a few thousandths of an inch, file it flat with the surrounding mounting collar of the frame. Careful and slowly, file then check, until it's flush. That will restore headspace so it won't slam fire/chain fire.
Mine has 2000 rounds through the original slide and barrel/frame. Even after these fixes, the slide breech face will continue to wear- and eventually you'll need a slide regardless- as the right side of slide starts to bulge out to the right, and top of slide snout starts to bend upward, from heavy use. This distortion occurs at the ejection port in the slide, which is the weak point.
The slides on these guns are sacrificial. The more you shoot them, the quicker they wear, and begin to malfunction. Shoot them until they begin to malfunction, and if cleaning doesn't fix the problem, then install a new slide- you'll be back to new specs on the headspace again.
There were reports of dirty Jennings J22 shooting better than the same gun cleaned. That's because the dirt in the gun, restored some headspace, holding the slide away from the barrel just a bit, and allowing the extractor to once again grab the case rim and extract/eject.
they really are pretty cool once you understand them. I have guns worth $2000 and still have a Jennings. If they made them out of hardened gunmetal steel, they'd last forever. They are a great little gun to carry fishing with shotshells, for snakes- like a little shotgun. Just don't trust the safety, I'd never carry one with a round chambered.
ps- an ultra-strong barrel slide spring, is not the answer, it slams the slide forward with even more force, causing the bolt face to wear quicker and sooner. Actually the weakest slide you can put in the gun, and it still functions, is the best- because then you can shoot cheaper low-velocity ammo, and it will still eject. Just like the old Browning Auto-5 shotgun with adjustable recoil setting for high brass and low brass loads, a stronger spring only works for high velocity ammo. To shoot low velocity ammo, you need a weaker spring- otherwise the force of the low power ammo, can't overcome the spring.